Resistance rheostat



March 26, 1929. H. G. SMITH 1,707,147

RESISTANCE RHEOSTQAT Filed Sept. 10, 1926 2 Sheets-Sheet 1 March 26, 1929. H. G. SMITH RESISTANCE RHEOSTAT Filed Sept. 10, 1926 2 Sheets-Sheet 2 abi ozmq Patented Mar. 26, 1929.

UNITED STATES HERBERT G. SMITH, OIE MARSHALL, TEXAS.

RESISTANCE RHEOSTAT.

Application filed September 10, 1926. Serial No. 134,639.

This invention relates to improvements in resistance rheostats, being directed more specifically to a liquid rheostat acting as a I switch in an incandescent lamp circuit.

The present invention is specifically adapted for use in an electric light circuit where it is desired to effect a lighting of the lamps from dim to bri ht throughout a prolonged duration.

A device of this character can have many uses, one of which would be in the poultry industry.

The poultry owner is desirous of extending and prolonging the light period of the day in winter when the daylight periods are short. To accomplish this through the means of artificial light, the lights should be turned on before daybreak and again turned on at night-fall. In turning the lights on in the morning they should be turned on dimly and gradually, increasing to their maximum brightness. At night-fall the reverse operation is necessary, the lights being turned on brilliantly and gradually dimmed out to nothing.

The present invention is provided to accomplish the above result and is so constructed that the operation from bright to dark and dark to bright requires approximately thirty minutes, which will give the chickens ample time to go to roost before darkness overtakes them in the evening. The thrity minutes period of operation in the morning will, of course, make the day thirty minutes longer by reason ofturning the chickens out one-half hour earlier than they would by reason of natural daylight. The device for bringing about the above described operations is automatic.

The primary object'of the invention is the provision of a device for controlling the brightness in incancescent lamps in an electric light circuit.

A further object of the invention is to provide a device for controlling the brightness of lamps in an electric light circuit through the medium of a resistance rheostat r. hich is automatic in operation and which is actuated by the medium of a weight.

A still further obiect of the invention is the provision of a device of the character described in which the posit-ion of the operating weight is shifted automatically by an electric solenoid.

A still further object of the invention is the provision of means for controlling the and F.

time required to effect a complete operation of the device. v

A still further and general object of the invention is the provision of a device which accomplishes the purposes outlined above, which will be efficient and inexpensive in operation, cheap of manufacture and which when once installed will require little or no attention.

Other objects, novel features of construction and improved results of the invention will appear from the following description and accompanying drawings.

In the drawings- Figure 1 is a front view of a time clock having mounted thereon a circuit making and breaking device, a portion of which is shown in section.

Fig. 2 is a diagrammatic layout of the entire device including the electric circuits.

Fig. 3 is an enlarged view in side elevation, showing the manner of mounting the solenoid and the construction of the solenoid circuiting contact members.

Fig. 4 is an enlarged view in vertical section showing the construction of the resistance rheostat.

Referring now to the drawings, particularly Fig. 2 thereof, it will be seen that the lights A are provided with current, from some suitable source of supply (not shown) through the negative wire 5 and the positive wire 6.

A time switch. B has a shunt lead 7 rom the negative lead 5. This shunt lead passes through the time switch and terminates in a fixed conduit 8.

The positive lead 6 has direct connection with the plunger cylinder 9 of the resistance rheostat C. A shunt lead from the positive current wire 6 is designated at 10 and has connection with the center of the coil 11 of the solenoid D. The lead wires 12 and 13 run from the opposite ends of the coil 11 to the solenoid contacting members E By reference to Fig. 3 of the drawing, it will be seen that the solenoid D is pivotally mounted as at 14: on suitable arms 15. The solenoid contact members E and F are in the form of points 16, which are horizontally adjustable in the depending arms 17, which are fastened as at 18 to the lower side of the solenoid. It will, therefore, be readily apparent that as the solenoid rocks upon its pivotal mounting, the contact points 16 are moved into and out of engagement with the fixed contact 8 of the time switch lead wire 7.

The solenoid is provided with. an iron core G, which is movable in the solenoid coil 11.

The resistance rheostat C comprises a stationary open top container 19, for the electrolyte 20. The plunger-cylinder 9 of the rheosta-t has a lower open end and a closed top 21. From the top of the plunger is an upwardly extending arm 22 having pivotal connection at 23 with an arm 2% which extends from the solenoid D. The plunger 9 is provided in its top with an outlet 25 carrying a valve 26.

The lower ends of the walls of the plunger 9 are provided with two outwardly extending reduced portions 27, which. are adapted to enter the cups 28 mounted in the bottom of the rheostat container 19. The cups 28 each carry a small amount of mercury 29.

As it may at times be desirable to switch the lights on independently of the rheostat, a lead 6 is taken off or". the positive current wire 6 in back of the rheostatand led to the lamp circuitin front of the rheostat. A switch '30 is positioned in this shunt circuit for controlling the same. This switch is normally open.

Referring to Fig. 1 of the drawings, in which the detailed construction of the time clock switch is shown, it will be seen that this clock is a twenty-four hour clock earrying a twenty-four dial 31. The shaft of the clock carries in place of the usual hands four extending arms 33, 34L, 35 and 36, the positions of which are adjustable on the shalt by reason of a thumb-nut 37. hese arms are of a length to extend slightly beyond the circumferential edge 01 the clock dial, their ends being tapered as at 38 tor engagement with the tapered extension 39 of the flexible contact member +1.0, which forms a part of the contact mechanism H. As clearly appears in Fig. 1 of the drawings, this contact making and breaking mechanism comprises a base li, supported on the front of the clock it .t above the dial by suitable bracket-s -l2. This base is provided with a concave portion 43 having an opening 4:4. through which the member 39 extends to a position to be engaged by the arms 33, 34;, 35 and 36.

As previously described, the time clock switch is in a shunt circuit taken from the negative main circuit wire 5. This shunt circuit comes into the making and breaking mechanism, being fastened thereto as at 4-5, so that electrical connection is had with a resilient member 46, which member carries the contact 40, above referred to.

Positioned immediately above the spring arm 46 and its contact 40, there is a second contact member 47, which is pivotally supported as at 4:8 to an upright 49. The contact arm i-T carries at one end a contact member 50, which is normally in separated relation to the contact member 10, while the opposite end of the arm 47 carries a contact 51, which is normally in engagement with the adjustable screw contact 52. The screw contact 52 is screw-threadedly mounted in an L-shaped bracket 53, which is fastened to the base all and is provided with a terminal 5% to which is connected the continuation of the shunt line 7, which runs to and ends in the lixed contact 8.

The contacts 51 and 52 are held normally in engagement by reason of the coiled spring 55.

It will be seen that in operation the arm 33 of the clock will strike the projection 39 of the spring arm 46, and it will carry the contact ll) upwardly into engagement with the contact 50, at which time the circuit will be momentarily closed. A continued movement of the arm 33 will rock the arm l? on its pivotal support and break the contact between the points 51 and When the arm 33 has passed beyond engagement with the extension 39, the spring 55 will pull the arm 47 back into the position shown in Fig. 1 of the drawings, wherein the circuit is broken between the points Q0 and 50, while the points 51 and 52 are closed.

Operation.

As will now be readily understood, the device described and illustrated is particularly adapted for use in the poultry bust ness, where it is desired to prolong the light, period of the short winter days. At this time of the year, it does not usually b06011)? very light until after 7.30 a. m.

Vith the above in mind and being desirous oit prolonging the light period ol' the day, the arm 33 of the time clock switch is set so that t will eng e the dowuwawi y extending in at up imately 5.31) a. in. The core 0' the solenoid is in the position shown. in Fig. 2 ot the drav. and has elevated the plunger 9 suilicie high to have removed the lower end of the plunger completely 'i'rom the electrolyte 20 in the corn minor 1%). The lights A will, oi course. be out as the positive side of the main circuit to the lights broken or opt-=1 at the rhecstat. i

As the arm 33 strikes the lug 39, the spring arm 426 is r l had until contact 1: between the points to and 50. The current Will now flow through the making and breaking mechanism H, as the points 51 and 52 are in engagement, to the tixed contact 8, which is in contact with the solenoid contact E. 'he upper halt ot the solenoid coil will now be energized, as current is flowing to the upper end of the coil. through the ill) lili

wire 12 and to the center of the coil through the shunt wire 10. Theoinstant that the upper half of the solenoid becomes energized, the core G is drawn upward into the energized end of the coil. This movement is almost instantaneous and the weight oi the core is now exerting a downward pr ssure upon the plunger 9 of the rheostat.

The continued movement of the arm 33 has caused the points 51 and 52 to become separated thus opening the circuit so that the solenoid coil has become momentarily deenergized. The still further forward movement of the arm 33 leaves the time switch shunt circuit open as appears in Fig. 1 of the drawings.

lVith the solenoid core exerting a downward pressure upon the plunger 9, the lower end of the plunger has entered the electrolyte and thus closed the main supply circuit to the lights, which will become dimly illuminated. The first illumination of the lights will be very dim as the current must pass through the high resistance of the full depth of the electrolyte to pass outwardly -from the bottom of the rheostatto the lights.

The plunger 9 will continue to descend by reason oi the force exerted by the core weight G. As the plunger descends into the electrolyte the resistance gradually diminishes and the lights will consequently gradually brighten. The time required for the plunger 9 to reach the bottom of the container is controlled by the valve 26, as the plunger must d scend against the air-pressure contained between its top 21 and the liquid electrolyte in the container 19. The valve 26 is set to permit the escape of this airpressure in an amount to permit the complete downward movement of the plunger in any predetermined specified period of time.

hen the plunger finally reaches the end of its downward movement, the reduced ends 27 of the plunger have entered the cups 528 and are submerged in the mercury 29, wherebypositive transmission oi the current to the li 'lits had without resistance, and i will be burning in their full the l ir i brilliancy.

From the i. regoing it will be seen that the light effect l rought about very slowly, wit 1 the result that the chickens will not be blinded by the sudden change from darkness to light. lily reason of the valve 26, the time duration required for the operation, of from darkness to light, can be adjusted to meet any requirement.

Alter the operation or lighting the lights has taken place, it is desirable to have a. reverse action of the device as daylight will have arrived and the burning of the lights will be a useless waste of current and expense.

The arm 34 of the time switch will now come into operation, it having been previously set to engage the extension lug 39 two and one-half hours later than the arm 83.

The reverse operation of the mechanism is practically a duplication of that just described.

By reason of the contacts E and F being rigidly attached to the solenoid, the contact E has moved from engagement with the fixed contact 8, while the contact F has been moved into contact position with the fixed contact 8.

Therefore it will be seen that when the arm 34, through engagement with the lug 39, closes the shunt circuit through the make and break mechanism H, the lower half of the solenoid coil 11 is energized, the current entering the lower end of the solenoid through the wire 18 and the center of the solenoid through the wire 10. Immediately upon the lower half of the solenoid coil becoming energized the core G is drawn into this half of the coil and assumes the position shown in Fig. 2 of the drawing. lVith the core in this position an upward force or pull is exerted upon the plunger 9.

The upward movement of the plunger is slow, however, as it must liittagainst the vacuum in the plunger between its top 21 and the liquid electrolyte. Here again the speed of the upward movement is controlled by the valve 26, which controls the admission of air into the plunger to relieve the vacuum.

The time clock arms 35 and 36 are properly positioned in the night period of the clock to accomplish a similar operation of the mechanism in the evening. As the evening operation of the device is similar to that just described in respect to morning, it is not necessary to go into and describe this second operation of the invention.

Although the invention has been shown and described for use in respect to poultry business and the control of an electric light circuit, the invention can be utilized in other ways. i r

The invention is really a time governed automatic electrolytic rheostat for controlling the current used in starting various electric: appliances, and its use need not be limited to electric light circuits. Many other uses could vbe found for the device without departing from the spirit oi the invention.

.Attention is directed tothe fact that the entire mechanism is entirely automatic and will continue to operate and perform its functions automatically so long as the time clock B is kept wound. The winding of the clock is the only manual operation called for, and this will need attention only occasionally, as an eight-day clock could readily be used.

Having thus described my invention, what I desire to claim and secure by Letters Patent is:

iii

1. In an electric rheostat, the combination of a tank containing a current conducting liquid, an electrode movable therein, a solenoid horizontally and pivotally mounted and having a movable weighted core, operative connection between the solenoid and the electrode, and means for energizing the solenoid for shifting the position of the weighted core thereo'l, whereby the electrode is moved into and out of the liquid in said tank for varying the resistance of the rheostat.

2. A circuit controlling device, co1uprising a liquid resistance rheostat operating as a switch, a movable electrode forming a part of said rheostat 'and adapted to be moved upwardly and downwardly in said liquid, said electrode in the form o't'an open ended vessel adapted to be moved downwardly into the liquid against air pressure and moved upwardly in the liquid against a vacuum, a solenoid horizontally and pivotally mounted in respect to said vessel electrode and having pivotal connection therewith, a coil in said solenoid having electrical connection whereby the coil is divided into two parts, a weighted core mounted for reciprocation in said solenoid coil, a switch for delivering the current to said solenoid coil at predetermined times, contact points carried by said solenoid and adapted for alternate contacting engagement with the switch circuit for alternately energizing the opposite ends of the coil, whereby the weight is alternately shifted to opposite ends of the solenoid for exerting alternating upward and downward pressure upon the vessel electrode, and means for controlling the admission of air-to the vessel electrode for controlling the speed of movement thereof.

A circuit controlling device comprising a container having therein a resistance current conducting liquid, an electrode movable therein, a solenoid pivotally mounted and having a movable weighted core, operative connection between the solenoid and the electrode, and means for energizing the solenoid for shifting the position oi the weighted core thereof, whereby the solenoid is rocked upon its pivotal mounting and the electrode moved into and out of the liquid for varying the resistance of the rheostat.

4. A resistance rheostat adapted for use in an electric light circuit where it is desired to ell'ect a lighting of the lamps in sa" d circuit from dim to bright or bright to dim over a period of prolonged duration, con1 prising a container having therein contacts connected with the electric circuit, said container carrying a resistance current conduct ing liquid, an electrode in said circuit and movable in said container and adapted for engagement with the contacts therein, a pivotally mounted solenoid carrying a movable weighted core, means to energize the opposite ends ot the solenoid, said electrode having-operative connection with said solenoid, said solenoid having a coil divided into two parts, a switch for delivering the current to said solenoid, contact points carried by said solenoid and adapted for contacting engagement with the switch for electrically energizing one or the other of the coils of the solenoid, and the weighted core of the solenoid shifted therein to one or the other of the sides of the pivotal. support of the solenoid for exerting either a do vnward or upward force upon the electrode for moving the same in the resistance liquid ot' the rheostat, for the purpose described.

5. A circuit controlling device comprising a liquid resistance rheostat operating as a switch, a movable electrode ii'orming a part of said rheostat adapted to be moved up wardly and downwardly in the liquid thereof, a solenoid horizontally and pivotally mounted and having operative connection with said electrode, said solenoid having a coil divided into two parts, a switch for delivering the current to said solenoid. contact points carried by said solenoid and adapted for contact engagement with the switch for selectively energizing one or the other of the coils of the solenoid, and the weighted core of the solenoid shifted therein to one or the other of the sides of the pivotal support ot the solenoid for exerting either a downward or upward force upon the electrode for moving the same in the resistance liquid of the rheostat, for the purpose described.

6. In a liquid rheostat, the combination of the tank containing current conducting liquid, oi? an electrode in the form of an open ended vessel movable into said liquid against air pressure and removable from said liquid against a vacuum, means to control the cape and admission of air to said (cs-ail tor controlling the speed of movement thereof, a solenoid horizontally and pivotally mounted and having operative connection with said electrode, said solenoid provided with a weighted core movable therein, and means to energize the solenoid to shift the weighted core 'i'rom one end oi the solenoid to the other, whereby said solenoid can be rocked upon its pivotal support for hitting or raising the electrode for reducing or increasing the resistance of the rheostat.

In testimony whereof I hereunto allix my signature.

HERBERT G. SMITH. 

